Role of the Thymus in Tolerance. II. Transfer of Specific Unresponsiveness to BSA with Thymus Grafting.

Abstract

Summary In rats thymectomized and irradiated as adults and grafted with thymus from adult donors given 150 mg of BSA over the 3-day period immediately preceding grafting, sensitization of the delayed type and antibody formation against BSA were both inhibited. An inhibition of lesser degree was observed in rats grafted with normal thymus and given BSA intravenously at the time of grafting or given marrow from pretreated donors. It is concluded that tolerance for certain immune responses is induced in the adult thymus, even in normal animals given large systemic doses of antigen which can penetrate this organ.